The role of prognostic factors in acute myeloid leukemia

The Acute Myelogenous Leukemia Cooperative Group in Germany studied the role of different intensities of induction therapy, all followed by similar postremission treatment. Of the 1,034 patients aged 16 to 83, 33 percent were over age 60, 63 percent attained a complete remission, and the overall relapse-free survival rate was 30 percent after 5 years. A significantly higher relapse-free survival was predicted by M3 morphology, a favorable karyotype, including t(8;21), t(15;17), and inv(16), and the absence of dysmyelopoiesis. In contrast, dysmyelopoiesis, high serum lactic dehydrogenase, age over 64, and unfavorable karyotype, including abnormalities of chromosomes 5 or 7 and complex abnormalities, all predicted a low relapse-free survival rate. No comparable impact on relapse-free survival was found from the two randomized different intensities of induction treatment in each age-group. Age, LDH, M3, and karyotype contributed to a prognostic index that identified good, intermediate, and poor prognostic groups. Patients older than age 60 showed significantly less frequent favorable and more frequent unfavorable karyotypes, and received generally less-intensive induction treatment than what younger patients were given. We conclude from this that, unlike some biologic disease characteristics, treatment variables are weak prognostic factors and high age per se may not be an independent factor of overall relapse-free survival.